1. Field of the Invention
The present invention relates to a camera and more particularly to a camera which prevents a failure in photographing caused by incorrectly holing the camera.
2. Description of the Related Art
A compact camera using a roll of 35 mm film is provided with an automatic electric flash equipment which automatically emits a strobe light in the dark, an AF mechanism which automatically performs focusing with half depression of a shutter release button, and an AE mechanism which automatically controls an exposure and the like, so that a beginner can easily take a picture.
In the above-described camera, it often happens that a strobe light emitting part, a taking lens, windows for automatic focusing, etc. are blocked or touched by a finger (Hereinafter, this is expressed as "finger obstruction"). That is, the failure in photographing is mostly caused by this finger obstruction.
For example, if the strobe light emitting part is obstructed by the finger at the time of photographing, a printed photograph is to be underexposure, and if the taking lens is obstructed, the finger is printed on the photograph. Moreover, when windows for automatic focusing or automatic exposure are obstructed by the finger, an accurate focusing or an exposure control cannot be carried out.
There are two cameras disclosed in Japanese Utility Model Application Laid-open No. 61-129 and Japanese Patent Application Laid-open No. 5-188437, which prevent a failure in photographing caused by the finger obstruction. Above-mentioned cameras aim to prevent a strobe light emitting part from being obstructed by the finger, and fine irregular portions and projections are formed around the strobe light emitting part so as to sense the finger obstruction. However, the irregular portions and projections are formed on an external surface of the camera, so there is a restriction in designing the external appearance of the camera, and also, there is a disadvantage in designing the camera to be compact.
Under the above-described circumstances, the camera of Japanese Patent Application Laid-open No. 6-10064 is provided with a touch sensor thereon, which electrically detects the finger obstruction which is caused by incorrect holding. The touch sensor is, for example, an electrostatic capacity type which is provided in the vicinity of a strobe light emitting window so as to detect the finger obstruction. Accordingly, a mechanically movable portion is not required, so that the designing of the external appearance is not restricted, and the camera has a durability. In this camera, the detection of the finger obstruction is performed by detecting the change of the electrostatic capacity at a detecting electrode. However, the electrostatic capacity at the detecting electrode is changed only if the finger gets close to the detecting electrode. As a result, there is a problem in that the finger obstruction is detected by mistake.
Furthermore, if the camera body is covered with a decoration face plate which is made of a metal having an electro-conductivity such as aluminum, titanium, nickel alloy and the like, the detecting electrode is located in such a manner to be close to or contact with the face plate. Therefore, the electrostatic capacity at the detecting electrode is changed by holding the camera body. As a result, there is a disadvantage in that the finger obstruction is frequently detected by mistake.
Moreover, in the case that the camera body is made of an electro-conductive material such as aluminum die casting and the like, the detecting electrode is located in such a manner to be close to or contact with the camera body. Therefore, if the finger contacts with a metal part such as a screw, etc. which are exposed to the outside, the electrostatic capacity at the detecting electrode is similarly changed even though the camera body is covered with an insulating face plate. Consequently, the finger obstruction is detected by mistake.